Suspension type Insulator
What is Suspension Type Insulator
A type of transmission line insulator that is used for voltage levels above 33 kV.
Basic Construction and Working of Suspension Type Insulator
It comprises of a number of porcelain discs that are connected in series by metal links in the form of string. One end of the string is secured to the cross-arm of the power transmission line, while the other end has a conductor suspended over it.
How it Looks
The figure below displays a Suspension type insulator string on a Power transmission line:
The figure below displays a single disc of glass type inslator:
In a suspension-type insulator assembly, a number of porcelain or glass-type insulators are connected using metal links to form a string. The figure below displays strings of suspension insulators formed from glass type single discs.
Every single disc is rated for low voltage, the number of discs in any string depends on the operating voltage of that line, the higher the voltage is the more the number of discs is.
Advantages of Suspension Type Insulators
A suspension-type insulator provides a couple of advantages when used in transmission lines. These include:
- For high voltage levels and medium voltage levels beyond 33 kV, suspension-type insulators are much more economical as compared to other types of insulators i.e pin type insulators.
- The string comprises discs, depending on required voltage levels, the number of discs can be increased or decreased.
- The overall arrangement is flexible, the connection of the string to the transmission line pole is in such a way that the insulator string is free to swing in any direction and it can take up a position where mechanical stresses are minimum.
- In case one or more discs are damaged, the whole string doesn’t become useless, rather the damaged discs can be replaced by new ones.
- In case the demand on a power system increases, and it is desired to increase voltage, the additional demand of required insulation can be fulfilled by adding more discs in the string